ac servo drives sigma-v series user's manual design and ... · 9 troubleshooting 9.1.1 list of...

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9Troubleshooting

9.1 Alarm Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-29.1.1 List of Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-29.1.2 Troubleshooting of Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6

9.2 Warning Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-219.2.1 List of Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-219.2.2 Troubleshooting of Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-22

9.3 Troubleshooting Malfunction Based on Operation and Conditions of the Servomotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-25

9 Troubleshooting

9.1.1 List of Alarms

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9.1 Alarm DisplaysThe following sections describe troubleshooting in response to alarm displays.

The alarm name, alarm meaning, alarm stopping method, alarm code output, and alarm reset capability are listed in order of the alarm numbers in 9.1.1 List of Alarms.

The causes of alarms and troubleshooting methods are provided in 9.1.2 Troubleshooting of Alarms.

9.1.1 List of AlarmsThis section provides list of alarms.

Servomotor Stopping MethodIf an alarm occurs, the servomotor can be stopped by doing either of the following operations.

Gr.1: The servomotor is stopped according to the setting in Pn001.0 if an alarm occurs. Pn001.0 is factory-set to stop the servomotor by applying the DB.

Gr.2: The servomotor is stopped according to the setting in Pn00B.1 if an alarm occurs. Pn00B.1 is factory-set to stop the servomotor by setting the speed reference to "0." The servomotor under force control will always use the Gr.1 method to stop. By setting Pn00B.1 to 1, the servomotor stops using the same method as Gr.1. When coordinating a number of servomotors, use this stopping method to prevent machine damage that may result due to differences in the stop method.

Alarm ResetAvailable:Removing the cause of alarm and then executing the alarm reset can clear the alarm. N/A:Executing the alarm reset cannot clear the alarm.

Alarm Number Alarm Name Meaning

Servo-motor

StoppingMethod

Alarm Reset

Alarm Code Output

ALO1 ALO2 ALO3

A.020 Parameter Checksum Error 1

The data of the parameter in the SERVO-PACK is incorrect. Gr.1 N/A

H H H

A.021 Parameter Format Error 1 The data of the parameter in the SERVO-PACK is incorrect. Gr.1 N/A

A.022 System Checksum Error 1 The data of the parameter in the SERVO-PACK is incorrect. Gr.1 N/A

A.030 Main Circuit Detector Error Detection data for main circuit is incorrect. Gr.1 Available

A.040 Parameter Setting Error 1 The parameter setting is outside the setting range. Gr.1 N/A

A.041 Encoder Output Pulse Setting Error

The encoder output resolution (Pn281) is outside the setting range or does not satisfy the setting conditions.

Gr.1 N/A

A.042 Parameter Combination Error

Combination of some parameters exceeds the setting range. Gr.1 N/A

A.050 Combination Error The SERVOPACK and the servomotor capacities do not match each other. Gr.1 Available

A.051 Unsupported Device Alarm The device unsupported was connected. Gr.1 N/A

A.080 Linear Scale Pitch Setting Error

The setting of the linear scale pitch (Pn282) has not been changed from the default set-ting.

Gr.1 N/A

A.0b0 Cancelled Servo ON Command Alarm

The servo ON signal (/S-ON) was sent from the host controller after executing a utility function that turns ON servomotor.

Gr.1 Available

A.100 Overcurrent or Heat Sink Overheated

An overcurrent flowed through the IGBT or the heat sink of the SERVOPACK was over-heated.

Gr.1 N/A L H H

9.1 Alarm Displays

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A.300 Regeneration Error Regenerative circuit or regenerative resistor is faulty. Gr.1 Available

L L HA.320 Regenerative Overload Regenerative energy exceeds regenerative resistor capacity. Gr.2 Available

A.330 Main Circuit Power Supply Wiring Error

• Setting of AC input/DC input is incorrect.• Power supply wiring is incorrect. Gr.1 Available

A.400 Overvoltage Main circuit DC voltage is excessively high. Gr.1 Available

H H LA.410 Undervoltage Main circuit DC voltage is excessively low. Gr.2 Available

A.450 Main-Circuit Capacitor Overvoltage

The capacitor of the main circuit has deteri-orated or is faulty. Gr.1 N/A

A.510 Overspeed The servomotor speed is above the maxi-mum speed. Gr.1 Available

L H L

A.511 Overspeed of Encoder Output Pulse Rate

The motor speed upper limit of the set encoder output resolution (Pn281) is exceeded.

Gr.1 Available

A.520 Vibration Alarm Incorrect vibration at the motor speed was detected. Gr.1 Available

A.521 Autotuning Alarm Vibration was detected while performing tuning-less function. Gr.1 Available

A.550 Maximum Speed Setting Error

The Pn385 setting is greater than the maxi-mum speed. Gr.1 Available

A.710 Overload: High LoadThe servomotor was operating for several seconds to several tens of seconds under a force largely exceeding ratings.

Gr.2 Available

L L L

A.720 Overload: Low Load The servomotor was operating continuously under a force exceeding ratings. Gr.1 Available

A.730A.731 Dynamic Brake Overload

When the dynamic brake was applied, mov-ing energy exceeded the capacity of dynamic brake resistor.

Gr.1 Available

A.740 Overload of Surge Current Limit Resistor

The main circuit power was frequently turned ON and OFF. Gr.1 Available

A.7A0 Heat Sink Overheated The heat sink of the SERVOPACK exceeded 100°C. Gr.2 Available

A.7AB Built-in Fan in SERVOPACK Stopped The fan inside the SERVOPACK stopped. Gr.1 Available

A.820 Encoder Checksum Error The checksum results of linear scale mem-ory is incorrect. Gr.1 N/A

H H H

A.840 Encoder Data Error Data in the linear scale is incorrect. Gr.1 N/A

A.850 Encoder Overspeed The linear scale was moving at high speed when the power was turned ON. Gr.1 N/A

A.860 Encoder Overheated The internal temperature of linear scale is too high. Gr.1 N/A

A.890 Encoder Scale Error A linear scale fault occurred Gr.1 N/A

A.891 Encoder Module Error Linear scale is faulty. Gr.1 N/A

A.A*1

SERVOPACK: Command Option Module Alarms − − − − − −

∗1. These alarms occur in SERVOPACKs with command option modules.For details, refer to the manual for the command option module that is connected.

(cont’d)


Servo-motor

StoppingMethod

Alarm Reset

Alarm Code Output

ALO1 ALO2 ALO3

9 Troubleshooting

9.1.1 List of Alarms

9-4

A.b10 Speed Reference A/D Error

The A/D converter for speed reference input is faulty. Gr.2 Available

H H H

A.b11 Speed Reference A/D Data Error

A/D conversion data of speed reference input is incorrect. Gr.2 Available

A.b20 Reference Force Input Read Error

The A/D converter for force reference input is faulty. Gr.2 Available

A.b31 Current Detection Error 1 The current detection circuit for phase U is faulty. Gr.1 N/A

A.b32 Current Detection Error 2 The current detection circuit for phase V is faulty. Gr.1 N/A

A.b33 Current Detection Error 3 The detection circuit for the current is faulty. Gr.1 N/A

A.bF0 System Alarm 0 "Internal program error 0" of the SERVO-PACK occurred. Gr.1 N/A





A.C10 Servo Overrun Detected The servomotor ran out of control. Gr.1 Available

L H L

A.C20 Phase Detection Error The detection of the phase is incorrect. Gr.1 N/A

A.C21 Hall Sensor Error The hall sensor is faulty. Gr.1 N/A

A.C22 Phase Information Disagreement The phase information does not match. Gr.1 N/A

A.C50 Polarity Detection Error The polarity detection failed. Gr.1 N/A

A.C51 Overtravel Detection at Polarity Detection

The overtravel signal was detected at polar-ity detection. Gr.1 Available

A.C52 Polarity Detection Uncompleted

The servomotor was turned ON under the condition of polarity detection uncom-pleted.

Gr.1 Available

A.C53 Out of Range for Polarity Detection

The moving distance exceeded the set value of Pn48E during polarity detection. Gr.1 N/A

A.C54 Polarity Detection Error 2 The polarity detection failed. Gr.1 N/A

A.C80 Absolute Encoder Clear Error

The data for the absolute linear scale was not properly cleared or set. Gr.1 N/A

A.C90 Encoder Communications Error

Communications between the SERVO-PACK and the linear scale is not possible. Gr.1 N/A

A.C91 Encoder Communications Position Data Error

A linear scale position data calculation error occurred. Gr.1 N/A

A.C92 Encoder Communications Timer Error

An error occurs in the communications timer between the linear scale and the SER-VOPACK.

Gr.1 N/A

A.CA0 Encoder Parameter Error Linear scale parameters are faulty. Gr.1 N/A

A.Cb0 Encoder Echoback Error Contents of communications with linear scale are incorrect. Gr.1 N/A

(cont’d)


Servo-motor

StoppingMethod

Alarm Reset

Alarm Code Output

ALO1 ALO2 ALO3

9.1 Alarm Displays

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A.d00 Position Error OverflowPosition error exceeded the value of exces-sive position error alarm level (Pn520) when the servomotor power is ON.

Gr.1 Available

L L H

A.d01 Position Error Overflow Alarm at Servo ON

This alarm occurs if the servomotor power is turned ON when the position error is greater than the set value of Pn526 while the servomotor power is OFF.

Gr.1 Available

A.d02Position Error Overflow Alarm by Speed Limit at Servo ON

When the position errors remain in the error counter, Pn584 limits the speed if the servo-motor power is turned ON. If Pn584 limits the speed in such a state, this alarm occurs when reference pulses are input and the number of position errors exceeds the value set for the excessive position error alarm level (Pn520).

Gr.2 Available

A.d30 Position Data Overflow The position feedback data exceeded ±1879048192. Gr.1 N/A

A.E71 Safety Option Module Detection Failure

Detection of the safety option module failed. Gr.1 N/A

H L LA.E74 Unsupported Safety Option Module

An unsupported safety option module was connected. Gr.1 N/A

A.E75 Unsupported Feedback Option Module

An unsupported feedback option module was connected. Gr.1 N/A

A.E81*2 SERVOPACK: Safety Module Alarm – – – – – –

A.Eb1 Safety Function Signal Input Timing Error

The safety function signal input timing is faulty. Gr.1 N/A H L L

A.Eb*2

SERVOPACK: Safety Module Alarms – – – – – –

A.EC*2

SERVOPACK: Safety Module Alarms – – – – – –

A.F10 Main Circuit Cable Open Phase

With the main power supply ON, voltage was low for more than 1 second in phase R, S, or T.

Gr.2 Available H L H

FL-1*3System Alarm Internal program error occurred in the SER-

VOPACK− N/A

UndefinedFL-2*3 − N/A

CPF00 Digital Operator Transmission Error 1 Digital operator (JUSP-OP05A-1-E) fails to

communicate with the SERVOPACK (e.g., CPU error).

− N/AUndefined

CPF01 Digital Operator Transmission Error 2 − N/A

A.− − Not an error Normal operation status − − H H H

∗2. These alarms occur in SERVOPACKs with safety modules.For details, refer to Σ-V Series User’s Manual, Safety Module (No.: SIEP C720829 06).

∗3. These alarms are not stored in the alarm history and are displayed only in the panel display.

(cont’d)


Servo-motor

StoppingMethod

Alarm Reset

Alarm Code Output

ALO1 ALO2 ALO3

9 Troubleshooting

9.1.2 Troubleshooting of Alarms

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9.1.2 Troubleshooting of AlarmsIf an error occurs in servo drives, an alarm display such as A. and CPF will appear on the panel operator.

Refer to the following table to identify the cause of an alarm and the action to be taken.Contact your Yaskawa representative if the problem cannot be solved by the described corrective action.

Alarm Number:Alarm Name

(Alarm Description)Cause Investigative Actions Corrective Actions

A.020:Parameter Checksum Error 1(The parameter data in the SERVOPACK is incorrect.)

The power supply voltage sud-denly dropped. Measure the power supply voltage.

Set the power supply voltage within the specified range, and set Fn005 to initialize the parameter.

The power supply went OFF while changing a parameter set-ting.

Check the circumstances when the power supply went OFF.

Set Fn005 to initialize the parameter and then set the parameter again.

The number of times that parame-ters were written exceeded the limit.

Check to see if the parameters were frequently changed through the host controller.

The SERVOPACK may be faulty. Replace the SERVOPACK.Reconsider the method of writing parameters.

Malfunction caused by noise from the AC power supply or grounding line, static electricity noise, etc.

Turn the power supply ON and OFF several times. If the alarm still occurs, there may be noise interfer-ence.

Take countermeasures against noise.

Gas, water drops, or cutting oil entered the SERVOPACK and caused failure of the internal components.

Check the installation conditions. The SERVOPACK may be faulty. Replace the SERVOPACK.

A SERVOPACK fault occurred.

Turn the power supply ON and OFF several times. If the alarm still occurs, the SERVOPACK may be faulty.

The SERVOPACK may be faulty. Replace the SERVOPACK.

A.021:Parameter Format Er-ror 1(The parameter data in the SERVOPACK is incorrect.)

The software version of SERVO-PACK that caused the alarm is older than that of the written parameter.

Check Fn012 to see if the set soft-ware version agrees with that of the SERVOPACK. If not, an alarm may occur.

Write the parameter of another SERVOPACK of the same model with the same software version. Then turn the power OFF and then ON again.

A SERVOPACK fault occurred. − The SERVOPACK may be faulty. Replace the SERVOPACK.

A.022:System Checksum Er-ror 1(The parameter data in the SERVOPACK is incorrect.)

The power supply voltage sud-denly dropped. Measure the power supply voltage. The SERVOPACK may be faulty.

Replace the SERVOPACK.The power supply went OFF while setting an utility function.

Check the circumstances when the power supply went OFF.


A SERVOPACK fault occurred.

Turn the power supply ON and OFF several times. If the alarm still occurs, the SERVOPACK may be faulty.


A.030:Main Circuit Detector Error


A.040:Parameter Setting Er-ror 1(The parameter setting was out of the setting range.)

The SERVOPACK and servomo-tor capacities do not match each other.

Check the combination of SERVO-PACK and servomotor capacities.

Select the proper combination of SERVOPACK and servomotor capacities.


The parameter setting is out of the setting range.

Check the setting ranges of the parameters that have been changed.

Set the parameter to a value within the setting range.

The electronic gear ratio is out of the setting range.

Check the electronic gear ratio. The ratio must satisfy:0.001< (Pn20E/Pn210) < 4000.

Set the electronic gear ratio in the range: 0.001< (Pn20E/Pn210) < 4000.

9.1 Alarm Displays

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A.041:Encoder Output Pulse Setting Error

The encoder output resolution (Pn281) is out of the setting range and does not satisfy the setting conditions.

Check the parameter Pn281. Set Pn281 to a correct value.

A.042:*1Parameter Combina-tion Error

The speed of program JOG oper-ation (Fn004) is lower than the setting range after having changed the electronic gear ratio (Pn20E/Pn210) or the servomo-tor.

Check if the detection conditions are satisfied.

Decrease the setting of the elec-tronic gear ratio (Pn20E/Pn210).

The speed of program JOG oper-ation (Fn004) is lower than the setting range after having changed the setting of the pro-gram JOG movement speed (Pn585).


Increase the setting of the program JOG movement speed (Pn585).

The moving speed of advanced autotuning is lower than the set-ting range after having changed the electronic gear ratio (Pn20E/Pn210) or the servomotor.


Decrease the setting of the elec-tronic gear ratio (Pn20E/Pn210).

A.050:Combination Error(The SERVOPACK and servomotor capacities do not correspond.)

The SERVOPACK and servomo-tor capacities do not match each other.

Check the capacities to see if they satisfy the following condition: Select the proper combination of

SERVOPACK and servomotor capacities.

A linear scale fault occurred. Replace the linear scale and see if the alarm occurs again. Replace the linear scale.


A.051:Unsupported Device Alarm

The parameters of the motor parameter file are not written in the linear scale. (Only when not using serial converter units)

Check if the parameters of the motor parameter file are written in the linear scale.

Write the parameters of the motor parameter file in the linear scale.

An unsupported serial converter unit or linear scale is connected to the SERVOPACK.

Check the product specifications, and select the correct model.

Select the correct combination of units.

A.080:Linear ScalePitch SettingError

The setting of the linear scale pitch (Pn282) has not been changed from the default setting.

Check the value of Pn282. Correct the value of Pn282.

A.0b0:Cancelled Servo ON Command Alarm

After executing the utility func-tion to turn ON the power to the motor, the servo ON signal (/S-ON) was sent from the host con-troller.

−Turn the SERVOPACK power sup-ply OFF and then ON again or exe-cute a software reset.

∗1. Detection conditionsIf one of the following conditions is detected, an alarm occurs.

•

•

(cont’d)Alarm Number:Alarm Name


≤ Servomotor capacitySERVOPACK capacity ≤ 41

4

× 10Number of divisions of serial converter unit

≤ Pn20EPn210Linear scale pitch [μm]

Pn585[mm/s]

×About 6.10 × 105

Number of divisions of serial converter unit ≥ Pn20E

Pn210Linear scale pitch [μm] Pn385 [100 mm/s]

9 Troubleshooting


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A.100:Overcurrent or Heat Sink Overheated(An overcurrent flowed through the IGBT or heat sink of SERVO-PACK overheated.)

Incorrect wiring or contact fault of main circuit cables.

Check the wiring. Refer to 3.1 Main Circuit Wiring. Correct the wiring.

Short-circuit or ground fault of main circuit cables.

Check for short-circuits across the servomotor terminal phases U, V, and W, or between the grounding and servomotor terminal phases U, V, or W. Refer to 3.1 Main Circuit Wiring.

The cable may be short-circuited. Replace the cable.

Short-circuit or ground fault inside the servomotor.

Check for short-circuits across the servomotor terminal phases U, V, and W, or between the grounding and servomotor terminal phases U, V, or W. Refer to 3.1 Main Circuit Wiring.

The servomotor may be faulty. Replace the servomotor.

Short-circuit or ground fault inside the SERVOPACK.

Check for short-circuits across the servomotor connection terminals U, V, and W on the SERVOPACK, or between the grounding and terminal U, V, or W. Refer to 3.1 Main Cir-cuit Wiring.


Incorrect wiring or contact fault of the regenerative resistor.

Check the wiring. Refer to 3.6 Con-necting Regenerative Resistors. Correct the wiring.

The dynamic brake (DB: Emer-gency stop executed from the SERVOPACK) was frequently activated, or the DB overload alarm occurred.

Check the power consumed by DB resistance (Un00B) to see how many times the DB has been used. Or, check the alarm history display Fn000 to see if the DB overload alarm A.730 or A.731 was reported.

Change the SERVOPACK model, operating conditions, or the mecha-nism so that the DB does not need to be used so frequently.

The generated regenerative resis-tor value exceeded the SERVO-PACK regenerative energy processing capacity.

Check the regenerative load ratio (Un00A) to see how many times the regenerative resistor has been used.

Check the operating condition including overload, and reconsider the regenerative resistor value.

The SERVOPACK regenerative resistance is too small.

Check the regenerative load ratio (Un00A) to see how many times the regenerative resistor has been used.

Change the regenerative resistance value to a value larger than the SERVOPACK minimum allowable resistance value.

A heavy load was applied while the servomotor was stopped or running at a low speed.

Check to see if the operating condi-tions are outside servo drive specifi-cations.

Reduce the load applied to the ser-vomotor or increase the operating speed.

Malfunction caused by noise interference.

Improve the wiring or installation environment, such as by reducing noise, and check to see if the alarm recurs.

Take countermeasures for noise, such as correct wiring of the FG. Use an FG wire size equivalent to the SERVOPACK main circuit wire size.

A SERVOPACK fault occurred. −

Turn the power supply OFF and then ON again. If the alarm still occurs, the SERVOPACK may be faulty. Replace the SERVOPACK.



9.1 Alarm Displays

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A.300:Regeneration Error

• Regenerative resistor capacity (Pn600) is set to a value other than 0 for a SGDV-R70, -R90, -1R6, -2R1, or -2R8 SERVO-PACK, and an external regen-erative resistor is not connected.

• An external regenerative resis-tor is not connected to the SGDV-550 or SGDV-260 SERVOPACK.

Check the external regenerative resistor connection and the value of the Pn600.

Connect the external regenerative resistor, or set Pn600 to 0 if no regenerative resistor is required.

The jumper between the power supply terminals B2 and B3 is removed for the SERVOPACKs other than the SERVOPACKs shown above.

Confirm that a jumper is mounted between the power supply terminals B2 and B3.

Correctly mount a jumper.

The external regenerative resis-tor is incorrectly wired, or is removed or disconnected.

Check the external regenerative resistor connection.

Correctly connect the external regenerative resistor.


While the main circuit power sup-ply is OFF, turn the control power supply OFF and then ON again. If the alarm still occurs, the SERVO-PACK may be faulty. Replace the SERVOPACK.

A.320:Regenerative Over-load

The power supply voltage exceeds the specified limit. Measure the power supply voltage. Set the power supply voltage within

the specified range.Insufficient external regenerative resistance, regenerative resistor capacity, or SERVOPACK capac-ity. Or, regenerative power has been continuously flowing back.

Check the operating condition or the capacity using the capacity selection Software SigmaJunma-Size+, etc.

Change the regenerative resistance, regenerative resistor capacity, or SERVOPACK capacity. Reconsider the operating conditions using the capacity selection software Sigma-JunmaSize+, etc.

Regenerative power continu-ously flowed back because nega-tive load was continuously applied.

Check the load applied to the servo-motor during operation.

Reconsider the system including servo, machine, and operating con-ditions.

The setting of parameter Pn600 is smaller than the external regener-ative resistor's capacity.


Set the Pn600 to a correct value.

The external regenerative resis-tance is too high. Check the regenerative resistance.

Change the regenerative resistance to a correct value or use an external regenerative resistor of appropriate capacity.




9 Troubleshooting


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A.330:Main Circuit Power Supply Wiring Error(Detected when the power to the main circuit is turned ON.)

The regenerative resistor discon-nected when the SERVOPACK power supply voltage was high.

Measure the resistance of the regen-erative resistor using a measuring instrument.

When using a regenerative resistor built in the SERVOPACK:Replace the SERVOPACK.When using an external regenera-tive resistor:Replace the external regenerative resistor.

In the AC power input mode, DC power was supplied.

Check the power supply to see if it is a DC power supply.

Correct the settings to match the actual power supply specifications.

In the DC power input mode, AC power was supplied.

Check the power supply to see if it is an AC power supply.

Correct the settings to match the actual power supply specifications.

Regenerative resistor capacity (Pn600) is set to a value other than 0 for a SGDV-R70, -R90, -1R6, -2R1, or -2R8 SERVO-PACK, and an external regenera-tive resistor is not connected.


Connect the external regenerative resistor, or set Pn600 to 0 if no regenerative resistor is required.

The jumper between the power supply terminals B2 and B3 is removed for the SERVOPACKs other than the SERVOPACKs shown above.

Confirm that a jumper is mounted between the power supply terminals B2 and B3.

Correctly mount a jumper.


A.400:Overvoltage(Detected in the SER-VOPACK main circuit power supply section.)

• For 100-VAC SERVOPACKs:The AC power supply voltage exceeded 145 V.



• For 200-VAC SERVOPACKs: with DC power supply input: The DC power supply voltage exceeded 410 V.

• For 400-VAC SERVOPACKs: The DC power supply voltage exceeded 820 V.

Measure the power supply voltage. Set AC/DC power supply voltage within the specified range.

The power supply is unstable, or was influenced by a lightning surge.

Measure the power supply voltage.

Improve the power supply condi-tions by installing a surge absorber, etc. Then, turn the power supply OFF and ON again. If the alarm still occurs, the SERVOPACK may be faulty. Replace the SERVOPACK.

Voltage for AC power supply was too high during acceleration or deceleration.

Check the power supply voltage and the speed and force during opera-tion.

Set AC power supply voltage within the specified range.

The external regenerative resis-tance is too high for the actual operating conditions.

Check the operating conditions and the regenerative resistance.

Select a regenerative resistance value appropriate for the operating conditions and load.

The mass ratio exceeded the allowable value.

Confirm that the mass ratio is within the allowable range.

Increase the deceleration time, or reduce the load.


Turn the control power OFF and then ON again while the main cir-cuit power supply is OFF. If the alarm still occurs, the SERVO-PACK may be faulty. Replace the SERVOPACK.



9.1 Alarm Displays

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A.410:Undervoltage(Detected in the SER-VOPACK main circuit power supply section.)

• For 100-VAC SERVOPACKs:The AC power supply voltage is 49 V or less.

• For 200-VAC SERVOPACKs: The AC power supply voltage is 120 V or less.

• For 400-VAC SERVOPACKs: The AC power supply voltage is 240 V or less.

Measure the power supply voltage. Set the power supply voltage within the specified range.

The power supply voltage dropped during operation. Measure the power supply voltage. Increase the power supply capacity.

Occurrence of instantaneous power interruption. Measure the power supply voltage.

When the instantaneous power cut hold time (Pn509) is set, decrease the setting.

The SERVOPACK fuse is blown out. −

Replace the SERVOPACK, con-nect a reactor, and run the SERVO-PACK.


A.450:Main-Circuit Capacitor Overvoltage

A SERVOPACK fault occurred. − Replace the SERVOPACK.

A.510:Overspeed(The servomotor speed exceeds the maximum.)

The order of phases U, V, and W in the servomotor wiring is incor-rect.

Check the motor wiring. Confirm that the servomotor is cor-rectly wired.

A reference value exceeding the overspeed detection level was input.

Check the input value. Reduce the reference value or adjust the gain.

The motor speed exceeded the maximum. Check the motor speed waveform.

Reduce the speed reference input gain, adjust the servo gain, or recon-sider the operating conditions.


A.511:Overspeed of Encoder Output Pulse Rate

The encoder output pulse fre-quency exceeded the limit.

Check the encoder output pulse set-ting.

Decrease the setting of the encoder output resolution (Pn281).

The encoder output pulse output frequency exceeded the limit because the motor speed was too high.

Check the encoder output pulse out-put setting and motor speed. Decrease the motor speed.

A.520:Vibration Alarm

Abnormal vibration was detected at the motor speed.

Check for abnormal noise from the servomotor, and check the speed and force waveforms during opera-tion.

Reduce the motor speed or reduce the speed loop gain (Pn100).

The mass ratio (Pn103) value is greater than the actual value or is greatly changed.

Check the mass ratio. Set the mass ratio (Pn103) to an appropriate value.

A.521:Autotuning Alarm(Vibration was detected while executing the one-parameter tuning, Easy-FFT, or tuning-less func-tion.)

The servomotor vibrated consid-erably while performing tuning-less function.

Check the motor speed waveform.

Reduce the load so that the mass ratio falls within the allowable value, or raise the load level using the tuning-less levels setting (Fn200) or reduce the rigidity level.

The servomotor vibrated consid-erably during one-parameter tun-ing or EasyFFT.

Check the motor speed waveform.Check the operation procedure of corresponding function and take a corrective action.



9 Troubleshooting


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A.550:Maximum Speed Set-ting Error

The Pn385 setting is greater than the maximum speed.

Check the value of Pn385 and Un010 (Monitor for allowable motor maximum speed and encoder output resolution).

Set Pn385 to a value equal to or lower than the motor maximum speed.

A.710:A.720:Overload A.710: High LoadA.720: Low Load

Incorrect wiring or contact fault of servomotor and linear scale. Check the wiring. Confirm that the servomotor and

linear scale are correctly wired.

Operation beyond the overload protection characteristics.

Check the servomotor overload characteristics and executed run command.

Reconsider the load conditions and operating conditions. Or, increase the motor capacity.

Excessive load was applied dur-ing operation because the servo-motor was not driven due to mechanical problems.

Check the executed operation refer-ence and motor speed. Remove the mechanical problems.

The setting of the linear scale pitch (Pn282) is incorrect. Check the setting of Pn282. Correct the setting of Pn282.

The setting of the motor phase selection (Pn080.1) is incorrect. Check the setting of Pn080.1. Correct the setting of Pn080.1.


A.730:A.731:Dynamic Brake Over-load(An excessive power consumption of dynamic brake was detected.)

The servomotor moves because of external force. Check the operation status.

Take measures to ensure the servo-motor will not move because of external force.

The moving energy at a DB stop exceeds the DB resistance capac-ity.

Check the power consumed by DB resistance (Un00B) to see how many times the DB has been used.

Reconsider the following:• Reduce the motor reference

speed.• Reduce the mass ratio.• Reduce the number of times of

the DB stop operation.


A.740:Overload of Surge Current Limit Resistor(The main circuit power is turned ON/OFF too frequently.)

The inrush current limit resistor operation frequency at the main circuit power supply ON/OFF operation exceeds the allowable range.

− Reduce the frequency of turning the main circuit power supply ON/OFF.


A.7A0:Heat Sink Overheated(Detected when the heat sink temperature exceeds 100°C.)

The surrounding air temperature is too high.

Check the surrounding air tempera-ture using a thermostat.

Decrease the surrounding air tem-perature by improving the SERVO-PACK installation conditions.

The overload alarm has been reset by turning OFF the power too many times.

Check the alarm history display (Fn000) to see if the overload alarm was reported.

Change the method for resetting the alarm.

Excessive load or operation beyond the regenerative energy processing capacity.

Check the accumulated load ratio (Un009) to see the load during oper-ation, and the regenerative load ratio (Un00A) to see the regenera-tive energy processing capacity.

Reconsider the load and operating conditions.

Incorrect SERVOPACK installa-tion orientation or/and insuffi-cient space around the SERVOPACK.

Check the SERVOPACK installa-tion conditions.

Install the SERVOPACK correctly as specified.




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A.7AB:Built-in Fan in SER-VOPACK Stopped

The fan inside the SERVOPACK stopped.

Check for foreign matter or debris inside the SERVOPACK.

Remove foreign matter or debris from the SERVOPACK. If the alarm still occurs, the SERVO-PACK may be faulty. Replace the SERVOPACK.

A.820:Encoder Checksum Error(Detected on the linear scale side.)

A linear scale fault occurred. − The linear scale may be faulty. Replace the linear scale.


A.840:Encoder Data Error(Detected on the linear scale side.)

A linear scale malfunctioned. −Turn the power supply OFF and then ON again. If the alarm still occurs, the linear scale may be faulty. Replace the linear scale.

Misreading of the linear scale occurred. −

Reinstall the linear scale, so the tol-erance is within the allowable range.

The speed of the linear scale exceeded the allowable range. −

Set the motor speed within the range specified by the linear scale manufacturer and restart the control power supply.

Malfunction of linear scale because of noise interference, etc. −

Correct the wiring around the linear scale by separating the linear scale connection cable from the servomo-tor main circuit cable or by check-ing the grounding and other wiring.

The hall sensor wiring is incor-rect. Check the hall sensor wiring. Correct the hall sensor wiring.

A hall sensor fault occurred. − Replace the hall sensor.

A.850:Encoder Overspeed(Detected when the con-trol power supply was turned ON.)(Detected on the linear scale side.)

The servomotor speed is higher than the specified speed when the control power supply was turned ON.

Check the motor moving speed (Un000) to confirm the servomotor speed when the power is turned ON.

Set the motor speed within the range specified by the linear scale manufacturer and restart the control power supply.

A linear scale fault occurred. −Turn the power supply OFF and then ON again. If the alarm still occurs, the linear scale may be faulty. Replace the linear scale.

A SERVOPACK fault occurred. −Turn the power supply OFF and then ON again. If the alarm still occurs, the SERVOPACK may be faulty. Replace the SERVOPACK.

A.860:Encoder Overheated(Only when an absolute linear scale is con-nected.)(Detected on the linear scale side.)

The ambient operating tempera-ture around the servomotor is too high.

Measure the ambient operating tem-perature around the servomotor.

The ambient operating temperature must be 40°C or less.

The motor load is greater than the rated load.

Check the accumulated load ratio (Un009) to see the load.

The motor load must be within the specified range.

A linear scale fault occurred. −Turn the power supply OFF and then ON again. If the alarm still occurs, the linear scale may be faulty. Replace the linear scale.

A SERVOPACK fault occurred. −Turn the power supply OFF and then ON again. If the alarm still occurs, the SERVOPACK may be faulty. Replace the SERVOPACK.

A.890:Encoder Scale Error A linear scale fault occurred. − The linear scale may be faulty.

Replace the linear scale.

A.891:Encoder Module Error A linear scale fault occurred. −

Turn the power supply OFF and then ON again. If the alarm still occurs, the linear scale may be faulty. Replace the linear scale.



9 Troubleshooting


9-14

A.b10:Speed Reference A/D Error(Detected when the servo is ON.)

A malfunction occurred in the speed reference input section. − Clear and reset the alarm and restart

the operation.



A.b11:Speed Reference A/D Data Error

A malfunction occurred in the speed reference input section. − Clear and reset the alarm and restart

the operation.



A.b20:Reference Force In-put Read Error(Detected when the servo is ON.)

A malfunction occurred in the reading section of the force refer-ence input.

− Clear and reset the alarm and restart the operation.



A.b31:Current Detection Er-ror 1

The current detection circuit for phase U is faulty. −



The current detection circuit for phase V is faulty. −



The detection circuit for the cur-rent is faulty. −


The servomotor main circuit cable is disconnected.

Check for disconnection of the ser-vomotor main circuit cable. Correct the servomotor wiring.

A.bF0:System Alarm 0 A SERVOPACK fault occurred. −






A.bF3:

System Alarm 3A SERVOPACK fault occurred. −






9.1 Alarm Displays

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A.C10:Servo Overrun Detect-ed(Detected when the servomotor power is ON.)

The order of phases U, V, and W in the servomotor wiring is incor-rect.

Check the motor wiring. Confirm that the servomotor is cor-rectly wired.

The setting of the motor phase selection (Pn080.1) is incorrect. Check the setting of Pn080.1. Correct the setting of Pn080.1.

A linear scale fault occurred. −

If the alarm still occurs after turning the power OFF and then ON again, even though the linear scale is cor-rectly wired, the linear scale may be faulty. Replace the linear scale.



A.C20:Phase Detection Error

The linear scale signal is weak. Check the voltage of the linear scale signal.

Fine-adjust the installation status of the linear scale head, or replace the linear scale.

The count-up direction of the lin-ear scale does not match the for-ward direction of the motor coil assembly.

Check the setting of Pn080.1 (Motor Phase Selection).Check the installation directions for the linear scale and motor coil assembly.

Change the setting of Pn080.1 (Motor Phase Selection).Correctly reinstall the linear scale and motor coil assembly.

The hall sensor signal is affected by noise. −

Correct the FG wiring and take measures against noise for the hall sensor wiring.

A.C21:Hall Sensor Error

The hall sensor is protruding from the motor magnetic way. Check the hall sensor. Correctly reinstall the motor coil

assembly or motor magnetic way.

The setting of the linear scale pitch (Pn282) is incorrect.

Check the setting of the linear scale pitch (Pn282).

Check the specifications of the lin-ear scale and correct the value of Pn282.

The hall sensor wiring is incor-rect. Check the hall sensor wiring. Correct the hall sensor wiring.

A hall sensor fault occurred. − Replace the hall sensor.A.C22:Phase Information Disagreement

The SERVOPACK phase data does not match that of the linear scale.

− Execute polarity detection (Fn080).

A.C50:Polarity Detection Er-ror

Parameter settings are incorrect. Check the linear scale specifications and feedback signal status.

The settings of the linear scale pitch (Pn282) and motor phase selection (Pn080.1) may not match the actual product requirements. Set these parameters to the correct values.

Noise interference occurred on the scale signal.

Check the wiring to see if:• Each FG of the serial converter

unit and servomotor is connected to the FG of the SERVOPACK.

• The FG of the SERVOPACK is connected to the FG of the power supply.

• The linear scale connection cables are securely shielded.

Check to see if the detection refer-ence is repeatedly output in one direction.

Take measures to avoid noise inter-ference by correctly connecting FG lines, shielding the linear scale con-nection cables, etc.



9 Troubleshooting


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A.C50:Polarity Detection Er-ror(cont’d)

An external force was applied to the motor coil assembly. −

The polarity cannot be properly detected if the detection reference is 0 (zero), but the speed feedback is not 0 (zero) because of an external force, such as cable tension, applied to the motor coil assembly.Take measures to reduce the exter-nal force so that the speed feedback becomes 0 for a 0 detection refer-ence.If external force cannot be reduced, increase the value of the changes in the sequence input signal allocation for each signal (Pn481).

The linear scale resolution is too low.

Check the linear scale pitch to see if it is within 100 μm.

If the linear scale pitch is 100 μm or longer, the SERVOPACK cannot detect the correct speed feedback.Use a scale pitch with higher accu-racy (a pitch within 40 μm recom-mended.) Or, increase the value of the polarity detection reference speed (Pn485). However, note that increasing the value of Pn485 will widen the servomotor movement range required for polarity detec-tion.

A.C51:OvertravelDetection at Polarity Detection

An overtravel signal was detected during polarity detection. Check the position after overtravel.

Perform the wiring for an overtravel signal. Execute polarity detection at a position where an overtravel sig-nal is not detected.

A.C52:Polarity Detection Un-completed

The servomotor has been turned ON under the following circum-stances.• Polarity detection was not yet

complete.• The /P-DET signal was not

input.

− Input the /P-DET signal.

A.C53:Out of Range for Po-larity Detection

The moving distance exceeded the set value of Pn48E in the mid-dle of detection.

−

Increase the value of the polarity detection range (Pn48E). Or, increase the value of the changes in the sequence input signal allocation for each signal (Pn481).

A.C54:Polarity Detection Er-ror 2

External force was applied to the servomotor. −

Increase the value of the polarity detection confirmation force refer-ence (Pn495).Increase the value of the polarity detection allowable error range (Pn498). Note that increasing the allowable error will also increase the motor temperature.

A.C80:Absolute Encoder Clear Error







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A.C90:Encoder Communica-tions Error

Contact fault of connector or incorrect wiring for linear scale connection cables.

Check the connector contact status for linear scale connection cables.

Re-insert the connectors and con-firm that the linear scale is correctly wired.

Cable disconnection for linear scale connection cables or short-circuit.Or, incorrect cable impedance.

Check the linear scale connection cables.

Use the cables with the specified rating.

Corrosion caused by improper temperature, humidity, or gas, short-circuit caused by intrusion of water drops or cutting oil, or connector contact fault caused by vibration.

Check the operating environment.

Improve the operating environmen-tal conditions, and replace the cable. If the alarm still occurs, replace the SERVOPACK.

Malfunction caused by noise interference. −

Correct the wiring around the linear scale by separating the linear scale connection cables from the servo-motor main circuit cable or by checking the grounding and other wiring.


Connect the servomotor to another SERVOPACK, and turn ON the control power. If no alarm occurs, the SERVOPACK may be faulty. Replace the SERVOPACK.

A.C91:Encoder Communica-tions Position Data Er-ror

Noise interference occurred on the I/O signal line because the linear scale connection cables are bent and the sheaths are dam-aged.

Check the linear scale connection cables and connectors.

Confirm that there is no problem with the cable layout.

The linear scale connection cables are bundled with a high-current line or near a high-current line.

Check the cable layout for linear scale connection cables.

Confirm that there is no surge volt-age on the cables.

The FG potential varies because of influence from machines on the servomotor side, such as the welder.


Properly ground the machines to separate from the linear scale FG.

A.C92:Encoder Communica-tions Timer Error

Noise interference occurred on the I/O signal line from the linear scale.

− Take countermeasures against noise for the linear scale wiring.

Excessive vibration and shocks were applied to the linear scale. Check the operating environment. Reduce the machine vibration or

correctly install the linear scale.





A.CA0:Encoder Parameter Error







9 Troubleshooting


9-18

A.Cb0:Encoder Echoback Er-ror

The wiring and contact for linear scale connection cables are incor-rect.

Check the wiring. Correct the wiring.

Noise interference occurred due to incorrect cable specifications of linear scale connection cables.

−

Use tinned annealed copper shielded twisted-pair or screened unshielded twisted-pair cable with a core of at least 0.12 mm2.

Noise interference occurred because the wiring distance for the linear scale connection cables are too long.

− The wiring distance must be 20 m max.

The FG potential varies because of influence from machines on the servomotor side, such as the welder.


Properly ground the machines to separate from linear scale FG.

Excessive vibration and shocks were applied to the linear scale. Check the operating environment. Reduce the machine vibration or

correctly install the linear scale.





A.d00:Position Error Over-flow (Position error exceeded the value set in the excessive position error alarm level (Pn520).)

The servomotor U, V, and W wir-ings is faulty.

Check the servomotor main circuit cable connection.

Confirm that there is no contact fault in the motor wiring or linear scale wiring.

The frequency of the position ref-erence pulse is too high.

Reduce the reference pulse fre-quency, and operate the SERVO-PACK.

Reduce the position reference pulse frequency or acceleration of posi-tion reference. Or, reconsider the electronic gear ratio.

The acceleration of the position reference is too high.

Reduce the reference acceleration, and operate the SERVOPACK.

Apply the smoothing function, such as using position reference accelera-tion/deceleration time constant (Pn216).

Setting of the excessive position error alarm level (Pn520) is low against the operating condition.

Check the alarm level (Pn520) to see if it is set to an appropriate value.

Set the Pn520 to proper value.



A.d01:Position Error Over-flow Alarm at Servo ON

This alarm occurs if the servomo-tor power is turned ON when the position error is greater than the set value of Pn526 while the ser-vomotor power is OFF.

Check the position error amount (Un008) while the servomotor power is OFF.

Set position error to be cleared while the servomotor power is OFF.Or, correct the excessive position error alarm level at servo ON (Pn526).

A.d02:Position Error Over-flow Alarm by Speed Limit at Servo ON

When the position errors remain in the error counter, Pn584 limits the speed if the servomotor power is ON. If Pn584 limits the speed in such a state, this alarm occurs when reference pulses are input and the number of position errors exceeds the value set for the excessive position error alarm level (Pn520).

−

Set position error to be cleared while the servomotor power is OFF.Or, correct the excessive position error alarm level (Pn520).Or, adjust the speed limit level at servo ON (Pn584).



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A.d30:Position Data Over-flow

The position data exceeded ±1879048192.

Check the input reference pulse counter (Un00C).

Reconsider the operating specifica-tions.

A.E71:Safety Option Module Detection Failure

The connection between the SERVOPACK and the safety option module is faulty.

Check the connection between the SERVOPACK and the safety option module.

Correctly connect the safety option module.

The safety option module was disconnected. –

Execute Fn014 (Resetting configu-ration error of option module) with using the digital operator or Sig-maWin+ and turn the power supply OFF and then ON again.

A safety option module fault occurred. – Replace the safety option module.

A SERVOPACK fault occurred. – Replace the SERVOPACK.

A.E74:Unsupported Safety Option Module

A safety option module fault occurred. − Replace the safety option module.

A unsupported safety option module was connected.

Refer to the catalog of the con-nected safety option module.

Connect a compatible safety option module.

A.E75:Unsupported Feed-back Option Module

A feedback option module fault occurred. − Replace the feedback option mod-

ule.

A unsupported feedback option module was connected.

Refer to the catalog of the con-nected feedback option module or the manual of the SERVOPACK.

Connect a compatible feedback option module.

A.Eb1:Safety Function Signal Input Timing Error

The lag between activations of the input signals /HWBB1 and /HWBB2 for the HWBB function is ten second or more.

Measure the time lag between the /HWBB1 and /HWBB2 signals.

The output signal circuits or devices for /HWBB1 and /HWBB2 or the SERVOPACK input signal circuits may be faulty. Alternatively, the input signal cables may be disconnected. Check if any of these items are faulty or have been disconnected.

A.F10:Main Circuit Cable Open Phase(With the main power supply ON, voltage was low for more than 1 sec-ond in an R, S, or T phase.)(Detected when the main power supply was turned ON.)

The three-phase power supply wiring is incorrect. Check the power supply wiring. Confirm that the power supply is

correctly wired.The three-phase power supply is unbalanced.

Measure the voltage at each phase of the three-phase power supply.

Balance the power supply by chang-ing phases.

A single-phase power is input without setting Pn00B.2 (power supply method for three-phase SERVOPACK) to 1 (single-phase power supply).

Check the power supply and the parameter setting.

Match the parameter setting to the power supply.



FL-1*2:System Alarm

SERVOPACK failure− Turn the power supply OFF and

then ON again. If the alarm still occurs, the SERVOPACK may be faulty. Replace the SERVOPACK.FL-2*2:

System Alarm−

∗2. These alarms are not stored in the alarm history and are displayed only in the panel display.



9 Troubleshooting


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CPF00:Digital Operator Transmission Error 1

The contact between the digital operator and the SERVOPACK is faulty.

Check the connector contact. Insert securely the connector or replace the cable.

Malfunction caused by noise interference. − Keep the digital operator or the

cable away from noise sources.

CPF01:Digital OperatorTransmission Error 2

A digital operator fault occurred. −

Disconnect the digital operator and then re-connect it. If the alarm still occurs, the digital operator may be faulty. Replace the digital operator.





9.2 Warning Displays

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9.2 Warning DisplaysThe following sections describe troubleshooting in response to warning displays.

The warning name, warning meaning, and warning code output are listed in order of the warning numbers in 9.2.1 List of Warnings.

The causes of warnings and troubleshooting methods are provided in 9.2.2 Troubleshooting of Warnings.

9.2.1 List of WarningsThis section provides list of warnings.

Note 1. Warning code is not output without setting Pn001.3 =1 (outputs both alarm codes and warning codes).2. If Pn008.2 = 1 (does not detect warning) is selected, no warnings will be detected except for an undervoltage

warning (A.971).

Warning Number Warning Name Meaning

Warning Code Output

ALO1 ALO2 ALO3

A.900 Position Error Overflow Position error exceeded the parameter setting (Pn520×Pn51E/100). H H H

A.901 Position Error Overflow Alarm at Servo ON

When the servomotor power is ON, the position error exceeded the parameter setting (Pn526×Pn528/100). H H H

A.910 OverloadThis warning occurs before the overload alarms (A.710 or A.720) occur. If the warning is ignored and operation contin-ues, an overload alarm may occur.

L H H

A.911 VibrationAbnormal vibration at the motor speed was detected. The detection level is the same as A.520. Set whether to output an alarm or warning by the vibration detection switch (Pn310).

L H H

A.920 Regenerative OverloadThis warning occurs before the regenerative overload alarm (A.320) occurs. If the warning is ignored and operation contin-ues, a regenerative overload alarm may occur.

H L H

A.921 Dynamic Brake OverloadThis warning occurs before dynamic brake overload alarm (A.731) occurs. If the warning is ignored and operation contin-ues, a dynamic brake overload alarm may occur.

H L H

A.941 Change of Parameters Requires Restart Parameters that require the restart have been changed. H H L

A.971 UndervoltageThis warning occurs before undervoltage alarm (A.410) occurs. If the warning is ignored and operation continues, an undervolt-age alarm may occur.

L L L

A.9A0 Overtravel Overtravel is detected while the servomotor power is ON. H L L

9 Troubleshooting

9.2.2 Troubleshooting of Warnings

9-22

9.2.2 Troubleshooting of WarningsRefer to the following table to identity the cause of a warning and the action to be taken. Contact your Yaskawa representative if the problem cannot be solved by the described corrective action.

Warning Num-ber: Warning

Name (Warning Description)

Cause Investigative Actions Corrective Actions

A.900: Position Error Overflow

The servomotor U, V, and W wirings is faulty.

Check the servomotor main circuit cable connection.

Confirm that there is no contact fault in the motor wiring or linear scale wir-ing.

The SERVOPACK gain is too low. Check the SERVOPACK gain. Increase the servo gain by using the

function such as advanced autotuning.

The frequency of the position reference pulse is too high.

Reduce the reference pulse frequency, and operate the SERVOPACK.

Reduce the position reference pulse frequency or acceleration of position reference. Or, reconsider the elec-tronic gear ratio.

The acceleration of the position reference is too high.

Reduce the reference acceleration, and operate the SERVOPACK.

Apply the smoothing function, such as using the position reference accelera-tion/deceleration time constant (Pn216).

Setting of the excessive position error alarm level (Pn520) is low against the operating condition.

Check the alarm level (Pn520) to see if it is set to an appropriate value. Set the Pn520 to proper value.



A.901: Position Error Overflow Alarm at Servo ON

When the servomotor power is ON, the posi-tion error exceeded the parameter setting (Pn526×Pn528/100).

−

Set Pn200.2 to 0 to clear the number of position error while the servomotor power is OFF. Or set an appropriate value for the excessive position error warning level at servo ON (Pn528).

A.910: Overload(Warning before alarm A.710 or A.720 occurs)

Incorrect wiring or con-tact fault of servomotor and linear scale.

Check the wiring. Confirm that the servomotor and lin-ear scale are correctly wired.

Operation beyond the overload protection characteristics.

Check the motor overload characteris-tics and executed run command.

Reconsider the load conditions and operating conditions. Or, increase the motor capacity.

Excessive load was applied during opera-tion because the servo-motor was not driven due to mechanical prob-lems.

Check the executed operation refer-ence and motor speed. Remove the mechanical problems.

A SERVOPACK fault occurred. − The SERVOPACK may be faulty.

Replace the SERVOPACK.

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A.911: Vibration

Abnormal vibration was detected at the motor speed.

Check for abnormal noise from the servomotor, and check the speed and force waveforms during operation.

Reduce the motor speed or reduce the servo gain by using the function such as one-parameter tuning.

The mass ratio (Pn103) value is greater than the actual value or is greatly changed.

Check the mass ratio. Set the mass ratio (Pn103) to an appropriate value.

A.920: Regenerative Overload(Warning before the alarm A.320 occurs)

The power supply volt-age exceeds the speci-fied limit.


Insufficient external regenerative resistance, regenerative resistor capacity, or SERVO-PACK capacity. Or, regenerative power has been continuously flowing back.

Check the operating condition or the capacity using the capacity selection Software SigmaJunmaSize+, etc.

Change the regenerative resistance, regenerative resistor capacity, or SER-VOPACK capacity. Reconsider the operating conditions using the capac-ity selection software SigmaJunma-Size+, etc.

Regenerative power continuously flowed back because negative load was continuously applied.

Check the load to the servomotor dur-ing operation.

Reconsider the system including servo drives, machine, and operating condi-tions.

A.921: Dynamic Brake Overload(Warning before the alarm A.731 occurs)

The servomotor moves because of external force.

Check the operation status.Take measures to ensure the servomo-tor will not move because of external force.

The moving energy at a DB stop exceeds the DB resistance capacity.

Check the power consumed by DB resistance (Un00B) to see how many times the DB has been used.

Reconsider the following:• Reduce the motor reference speed.• Reduce the mass ratio.• Reduce the number of times of the

DB stop operation.



A.941: Change of Pa-rameters Re-quires Restart

Parameters that require the restart have been changed.

− Turn OFF the power and ON again.

(cont’d)




9 Troubleshooting

9.2.2 Troubleshooting of Warnings

9-24

A.971: Under-voltage

• For 100 VAC SER-VOPACKs:The AC power supply voltage is 60 V or less.

• For 200-VAC SER-VOPACKs:The AC power supply voltage is 140 V or less.

• For 400-VAC SER-VOPACKs:The AC power supply voltage is 280 V or less.


The power supply volt-age dropped during operation.

Measure the power supply voltage. Increase the power supply capacity.

Occurrence of instanta-neous power interrup-tion.

Measure the power supply voltage.When the instantaneous power cut hold time (Pn509) is set, decrease the setting.

The SERVOPACK fuse is blown out. − Replace the SERVOPACK and con-

nect a reactor to the SERVOPACK.



A.9A0: Overtrav-el(Overtravel status is detected.)

When the servomotor power is ON, over-travel status is detected.

Check the input signal monitor (Un005) to check the status of the overtravel signals.

Refer to 9.3 Troubleshooting Malfunc-tion Based on Operation and Condi-tions of the Servomotor. Even if overtravel signals were not shown by the input signal monitor (Un005), momentary overtravel may have been detected. Take the following precau-tions. • Do not specify movements that

would cause overtravel from the host controller.

• Check the wiring of the overtravel signals.

• Take countermeasures for noise.

(cont’d)




9.3 Troubleshooting Malfunction Based on Operation and Conditions of the Servomotor

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9.3 Troubleshooting Malfunction Based on Operation and Conditions of the ServomotorTroubleshooting for the malfunctions based on the operation and conditions of the servomotor is provided in this section.

Be sure to turn OFF the servo system before troubleshooting items shown in bold lines in the table.

Problem Probable Cause Investigative Actions Corrective Actions

Servomotor Does Not Start

The control power supply is not ON.

Check voltage between control power terminals. Correct the wiring.

The main circuit power supply is not ON.

Check the voltage between main circuit power terminals. Correct the wiring.

Wiring of I/O signal connector CN1 is faulty or disconnected.

Check if the connector CN1 is prop-erly inserted and connected.

Correct the connector CN1 connec-tion.

Wiring for servomotor main circuit cable or linear scale connection cables is disconnected.

Check the wiring. Correct the wiring.

Overloaded Run under no load and check the load status.

Reduce load or replace with larger capacity servomotor.

Linear scale type differs from parameter setting (Pn002.2).

Check the settings for parameter Pn002.2.

Set parameter Pn002.2 to the linear scale type being used.

Speed/position references not input Check the allocation status of the input signals.

Allocate input signals so that the speed/position reference is input correctly.

Settings for the input signal selec-tions (Pn50A to Pn50D) is incor-rect.

Check the settings for parameters Pn50A to Pn50D.

Correct the settings for parameter Pn50A to Pn50D.

Servo ON signal (/S-ON) stays OFF.

Check the settings for parameters Pn50A.0 and Pn50A.1.

Set the parameters Pn50A.0 and Pn50A.1 to turn the /S-ON signal ON.

/P-CON input function setting is incorrect.

Check the settings for parameter Pn000.1.

Set parameters to match the applica-tion.

SEN input is OFF. Check the ON/OFF status of the SEN input.

If using an absolute linear scale, turn the SEN input signal ON.

Reference pulse mode selection is incorrect.

Check the Pn200.0 setting and the reference pulse form.

Match the Pn200.0 setting and the reference pulse form.

Speed control: Speed reference input is incorrect.

Check V-REF and SG to confirm if the control method and the input are agreed.

Correct the control method selec-tion parameter, and the input signal.

Force control: Force reference input is incorrect.



Position control: Reference pulse input is incorrect.

Check Pn200.0 reference pulse form and sign + pulse signal.


Position error clear (/CLR) input has not been turned OFF.

Check /CLR input signals (CN1-14 and -15). Turn /CLR input signals OFF.

The forward run prohibited (P-OT) and reverse run prohibited (N-OT) input signals are turned OFF.

Check P-OT or N-OT input signal. Turn P-OT or N-OT input signal ON.

The safety input signal (/HWBB1 or /HWBB2) remains OFF.

Check the /HWBB1 and /HWBB2 input signal.

Set the /HWBB1 and /HWBB2 input signal to ON.When not using the safety function, mount the safety function jumper connector (provided as an acces-sory) on the CN8.


9 Troubleshooting

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Servomotor Does Not Start (cont’d)

The polarity detection is not exe-cuted.

Check the parameter Pn080.0. Correct the setting of Pn080.0.

Check the /S-ON or /P-DET input signal.

• When using an incremental linear scale, turn ON the /S-ON or /P-DET input signal.

• When using an absolute linear scale, turn OFF the external /S-ON input signal and execute Fn080.

Servomotor Moves Instanta-neously, and then Stops

Servomotor wiring is incorrect. Check the wiring. Correct the wiring.

Serial converter unit wiring is incor-rect. Check the wiring. Correct the wiring.

Linear scale wiring is incorrect. Check the wiring. Correct the wiring.

Linear scale pitch (Pn282) is incor-rect. Check the setting of Pn282. Correct the setting of Pn282.

Linear scale counting up direction and servomotor coil assembly for-ward direction do not agree.

Check the directions.

Change the setting of Pn080.1 (Motor Phase Selection).Match the linear scale direction and coil assembly direction.

Polarity detection is not performed correctly.

Check if the value of Un004 (elec-trical angle 2 from polarity origin) at an arbitrary position is between ±10 degrees.

Correct the settings for the polarity detection related parameter.

Servomotor Speed Unstable

Wiring connection to servomotor is defective.

Check connections of power line (phases U, V, and W) and serial converter unit connectors.

Tighten any loose terminals or con-nectors and correct the wiring.

Servomotor Moves Without Reference Input

Speed control: Speed reference input is incorrect.



Force control: Force reference input is incorrect.



Speed reference offset is incorrect. The SERVOPACK offset is adjusted incorrectly. Adjust the SERVOPACK offset.

Position control: Reference pulse input is incorrect.

Check the reference pulse form (Pn200.0) and sign + pulse signal.



Linear scale counting up direction and servomotor coil assembly for-ward direction do not agree.

Check the directions.

Change the setting of Pn080.1 (Motor Phase Selection).Match the linear scale direction and servomotor direction.




Dynamic Brake Does Not Operate

Improper Pn001.0 setting Check the setting for parameter Pn001.0.

Correct the setting for parameter Pn001.0.

DB resistor disconnectedCheck if excessive mass, motor overspeed, or DB frequently acti-vated occurred.

Replace the SERVOPACK, and reduce the load.

DB drive circuit fault −There is a defective component in the DB circuit. Replace the SER-VOPACK.

(cont’d)



9-27

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Abnormal Noise from Servomotor

The servomotor largely vibrated during execution of tuning-less function.

Check the motor speed waveform.

Reduce the load so that the mass ratio becomes within the allowable value, or increase the load level or lower the tuning level for the tun-ing-less levels setting (Fn200).

Mounting is not secured. Check if there are any loose mount-ing screws. Tighten the mounting screws.

Vibration source at the driven machine.

Check for any foreign matter, dam-age, or deformations on the machin-ery's movable parts.

Contact the machine manufacturer.

Noise interference due to incorrect I/O signal cable specifications.

The I/O signal cable must be tinned annealed copper shielded twisted-pair or screened unshielded twisted-pair cable with a core of 0.12 mm2 min.

Use the specified I/O signal cable.

Noise interference due to length of I/O signal cable.

Check the length of the I/O signal cable.

The I/O signal cable length must be no more than 3 m.

Noise interference due to incorrect cable specifications of linear scale connection cables.

The linear scale connection cables must be tinned annealed copper shielded twisted-pair or screened unshielded twisted-pair cable with a core of 0.12 mm2 min.

Use the specified linear scale con-nection cables.

Noise interference due to length of linear scale connection cables.

Check the length of the linear scale connection cables.

The length of each cable must be equal to or shorter than the maxi-mum wiring length listed here.• Connection cables for serial con-

verter unit: 20 m• Connection cables for linear

scale: 15 m• Connection cables for hall sensor:

15 m

Noise interference due to damaged linear scale connection cables.

Check if the linear scale connection cables are bent and the sheaths are damaged.

Replace the linear scale connection cables and correct the cable layout.

Excessive noise to the linear scale connection cables.

Check if the linear scale connection cables are bundled with a high-cur-rent line or near a high-current line.

Correct the cable layout so that no surge is applied.

The FG potential varies because of influence from machines on the ser-vomotor side, such as the welder.

Check if the machines are correctly grounded.

Properly ground the machines to separate from the linear scale FG.

SERVOPACK pulse counting error due to noise interference

Check if there is noise interference on the I/O signal line from the linear scale.

Take measures against noise in the linear scale wiring.

Excessive vibration and shock to the linear scale

Check if vibration from the machine occurred or linear scale installation is incorrect (mounting surface accu-racy and fixing method).

Reduce vibration from the machine, or secure the linear scale installa-tion.

Serial converter unit fault − Replace the serial converter unit.

A linear scale fault occurred. − Replace the linear scale.

Servomotor Vi-brates at Fre-quency of Approx. 200 to 400 Hz.

Unbalanced servo gains Check to see if the servo gains have been correctly adjusted. Execute the advanced autotuning.

Speed loop gain value (Pn100) too high.

Check the speed loop gain (Pn100).Factory setting: Kv = 40.0 Hz

Reduce the speed loop gain (Pn100).

Position loop gain value (Pn102) too high.

Check the position loop gain (Pn102).Factory setting: Kp = 40.0/s

Reduce the position loop gain (Pn102).

(cont’d)


9 Troubleshooting

9-28

Servomotor Vibrates at Frequency of Approx. 200 to 400 Hz. (cont’d)

Incorrect speed loop integral time constant (Pn101)

Check the speed loop integral time constant (Pn101).Factory setting: Ti = 20.0 ms

Correct the speed loop integral time constant (Pn101).

Incorrect mass ratio (Pn103) Check the mass ratio (Pn103). Correct the mass ratio (Pn103).

High Motor Speed Overshoot on Starting and Stop-ping

Unbalanced servo gains Check to see if the servo gains have been correctly adjusted. Execute the advanced autotuning.

Speed loop gain value (Pn100) too high

Check the speed loop gain (Pn100).Factory setting: Kv = 40.0 Hz

Reduce the speed loop gain (Pn100).

Position loop gain value (Pn102) too high

Check the position loop gain (Pn102).Factory setting: Kp = 40.0/s

Reduce the position loop gain (Pn102).

Incorrect speed loop integral time constant (Pn101)

Check the speed loop integral time constant (Pn101).Factory setting: Ti = 20.0 ms

Correct the speed loop integral time constant (Pn101).

Incorrect mass ratio data (Pn103) Check the mass ratio (Pn103). Correct the mass ratio (Pn103).

The force reference is saturated. Check the force reference wave form. Use the mode switch function.

The force limit (Pn483, Pn484) is set to the initial value.

Initial value of force limit:Pn483 = 30%Pn484 = 30%

Set a appropriate value for Pn483 and Pn484 (Force Limit).

Absolute Linear Scale Position Dif-ference Error (The position saved in the host controller when the power was turned OFF is different from the position when the power was next turned ON.)

Noise interference due to incorrect cable specifications of linear scale connection cables.

The linear scale connection cables must be tinned annealed copper shielded twisted-pair or screened unshielded twisted-pair cable with a core of 0.12 mm2 min.

Use the specified linear scale con-nection cables.






15 m

Noise interference due to damaged linear scale connection cables.


Replace the linear scale connection cables and correct the cable layout.

Excessive noise to the linear scale connection cables.


Correct the cable layout so that no surge is applied.

FG potential varies because of influence of machines such as weld-ers at the servomotor.


Ground machines correctly, and prevent diversion to the FG on the linear scale side.

SERVOPACK pulse counting error due to noise interference

Check if there is noise interference on the I/O signal line from the serial converter unit.

Take measures against noise in the serial converter unit wiring.



Reduce vibration from the machine, or secure the linear scale installa-tion.

A linear scale fault occurred. − Replace the linear scale.A SERVOPACK fault occurred.(The pulse count does not change.) − Replace the SERVOPACK.

(cont’d)



9-29

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Absolute Linear Scale Position Dif-ference Error (The position saved in the host controller when the power was turned OFF is different from the position when the power was next turned ON.)(cont’d)

Host controller serial data reading error

Check the error detection section of the host controller.

Correct the error detection section of the host controller.

Check if the host controller is exe-cuting data parity checks. Execute a serial data parity check.

Check noise in the cable between the SERVOPACK and the host con-troller.

Take measures against noise, and again execute a serial data parity check.

Overtravel (OT)

Forward or reverse run prohibited signal is input.

Check the external power supply (+24 V) voltage for the input signal.

Correct the external power supply (+24 V) voltage.

Check if the overtravel limit switch operates properly. Correct the overtravel limit switch.

Check if the overtravel limit switch is wired correctly.

Correct the overtravel limit switch wiring.

Check the settings for parameters Pn50A and Pn50B.

Correct the settings for parameters Pn50A and Pn50B.

Forward or reverse run prohibited signal malfunctioning.

Check the fluctuation of the exter-nal power supply (+24 V) voltage for the input signal.

Stabilize the external power supply (+24 V) voltage.

Check if the overtravel limit switch operates correctly. Correct the overtravel limit switch.

Check if the overtravel limit switch wiring is correct. (check for dam-aged cables or loose screws.)

Correct the overtravel limit switch wiring.

Incorrect forward or reverse run prohibited signal (P-OT/N-OT) allocation (parameters Pn50A.3, Pn50B.0)

Check if the P-OT signal is allo-cated in Pn50A.3.

If another signal is allocated in Pn50A.3, allocate P-OT.

Check if the N-OT signal is allo-cated in Pn50B.0.

If another signal is allocated in Pn50B.0, allocate N-OT.

Incorrect servomotor stop method selection

Check the settings for parameters Pn001.0 and Pn001.1 when the ser-vomotor power is OFF.

Select a servomotor stop method other than "coast to stop."

Check the settings for parameters Pn001.0 and Pn001.1 when in force control.

Select a servomotor stop method other than "coast to stop."

Improper Stop Po-sition by Overtrav-el (OT) Signal

Improper limit switch position and dog length − Install the limit switch at the

appropriate position.The overtravel limit switch position is too short for the coasting distance.

− Install the overtravel limit switch at the appropriate position.

Position Error (Without Alarm)

Noise interference due to incorrect linear scale connection cable speci-fications

The linear scale connection cable must be tinned annealed copper shielded twisted-pair or screened unshielded twisted-pair cable with a core of 0.12 mm2 min.

Use the specified linear scale con-nection cable.






15 m

Noise influence due to damaged lin-ear scale connection cables.


Replace the linear scale connection cables and modify the cable layout.

(cont’d)


9 Troubleshooting

9-30

Position Error (Without Alarm)(cont’d)

Excessive noise to linear scale con-nection cables.


Change the cable layout so that no surge is applied.

The FG potential varies because of influence from machines on the ser-vomotor side such as the welder.


Properly ground the machines linear scale FG.

SERVOPACK pulse count error due to noise

Check if the I/O signal line from the serial converter unit is influenced by noise.

Take measures against noise in the serial converter unit wiring.



Reduce the machine vibration or mount the linear scale securely.

Noise interference due to improper I/O signal cable specifications


Use input signal cable with the specified specifications.

If the reference pulse input multipli-cation switching function is being used, noise may be causing the I/O signals (/PSEL and /PSELA) used for this function to be falsely detected.


Use input signal cable that satisfy specifications.

Noise interference due to length of I/O signal cable Check the I/O signal cable length. The I/O signal cable length must be

no more than 3 m.

A linear scale fault occurred. (The pulse count does not change.) − Replace the linear scale.


Servomotor Over-heated

Ambient operating temperature too high

Measure the servomotor ambient operating temperature.

Reduce the ambient operating tem-perature to 40°C or less.

Servomotor surface dirty Visually check the surface. Clean dust and oil from the surface.

Servomotor overloaded Check the load status with monitor.If overloaded, reduce load or replace with larger capacity SER-VOPACK and servomotor.




(cont’d)


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